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1. 1-4 Bar Graphs and Histograms Warm Up Problem of the Day Lesson Presentation Course 2

2. 1-4 Bar Graphs and Histograms Course 2 Warm Up Use the data below to answer the questions. 35, 45, 48, 53, 53, 27, 66, 36, 24 1. What is the mean? 2. What is the median? 3. What is the mode? 4. What is the range? 43 45 53 42

3. 1-4 Bar Graphs and Histograms Course 2 Problem of the Day Which number does not belong with the others? Why? 81, 64, 36, 27, 49 Possible answer: 27; the others are perfect squares.

4. 1-4 Bar Graphs and Histograms Course 2 Learn to display and analyze data in bar graphs and histograms.

5. 1-4 Bar Graphs and Histograms Course 2 Vocabulary bar graph double-bar graph histogram

6. 1-4 Bar Graphs and Histograms Course 2 Hundreds of different languages are spoken around the world. The graph shows the numbers of native speakers of four languages. A bar graph can be used to display and compare data. The scale of a bar graph should include all the data values and be easily divided into equal intervals.

7. 1-4 Bar Graphs and Histograms Course 2 Additional Example 1A: Interpreting a Bar Graph Use the bar graph to answer the question. A. Which language has the fewest native speakers? The bar for Spanish is the shortest, so Spanish has the fewest native speakers.

8. 1-4 Bar Graphs and Histograms Course 2 Additional Example 1B: Interpreting a Bar Graph Use the bar graph to answer the question. B. About how many more people speak Hindi than Spanish? About 50 million more people speak Hindi than speak Spanish.

9. 1-4 Bar Graphs and Histograms Course 2 Try This: Example 1A Use the bar graph to answer the question. A. Which fruit was eaten the most? The bar for bananas is the longest, so bananas were eaten the most.

10. 1-4 Bar Graphs and Histograms Course 2 Try This: Example 1B Use the bar graph to answer the question. B. About how many more pounds of apples than pounds of grapes were eaten per person? About 10 pounds more apples were eaten than grapes per person.

11. 1-4 Bar Graphs and Histograms Course 2 You can use a double-bar graph to compare two related sets of data.

12. 1-4 Bar Graphs and Histograms State Urban Rural Florida 65 mi/h 70 mi/h Texas 70 mi/h 70 mi/h Vermont 55 mi/h 65 mi/h Course 2 Additional Example 2: Making a Double-Bar Graph The table shows the speed limits of three states on interstate highways. Make a double-bar graph of the data. Step 1: Choose a scale and interval for the vertical axis. 80 60 40 20 0

13. 1-4 Bar Graphs and Histograms 80 60 40 20 0 State Urban Rural Florida 65 mi/h 70 mi/h Texas 70 mi/h 70 mi/h Vermont 55 mi/h 65 mi/h Course 2 Additional Example 2 Continued Step 2: Draw a pair of bars for each state’s data. Use different colors to show urban and rural speed limits.

14. 1-4 Bar Graphs and Histograms 80 60 40 20 0 State Urban Rural Florida 65 mi/h 70 mi/h Texas 70 mi/h 70 mi/h Vermont 55 mi/h 65 mi/h Course 2 Additional Example 2 Continued Step 3: Label the axes and give the graph a title. Speed Limit on Rural and Urban Highways Miles per hour TX FL VT

15. 1-4 Bar Graphs and Histograms 80 60 40 20 0 State Urban Rural Florida 65 mi/h 70 mi/h Texas 70 mi/h 70 mi/h Vermont 55 mi/h 65 mi/h Course 2 Additional Example 2 Continued Step 4: Make a key to show what each bar represents. Speed Limit on Rural and Urban Highways Miles per hour TX FL VT Urban Rural

16. 1-4 Bar Graphs and Histograms Pet Class A Class B Dog 12 14 Cat 9 8 Bird 2 3 Course 2 Try This: Example 2 The table shows the number of pets owned by students in two classes. Step 1: Choose a scale and interval for the vertical axis. 16 12 8 4 0

17. 1-4 Bar Graphs and Histograms 16 12 8 4 0 Pet Class A Class B Dog 12 14 Cat 9 8 Bird 2 3 Course 2 Try This: Example 2 Step 2: Draw a pair of bars for each pet’s data. Use different colors to show class A and class B.

18. 1-4 Bar Graphs and Histograms 16 12 8 4 0 Pet Class A Class B Dog 12 14 Cat 9 8 Bird 2 3 Course 2 Try This: Example 2 Step 3: Label the axes and give the graph a title. Pets Owned in Two Classes Number of pets Cat Bird Dog

19. 1-4 Bar Graphs and Histograms 16 12 8 4 0 Pet Class A Class B Dog 12 14 Cat 9 8 Bird 2 3 Course 2 Try This: Example 2 Step 4: Make a key to show what each bar represents. Pets Owned in Two Classes Number of pets Cat Bird Dog Class A Class B

20. 1-4 Bar Graphs and Histograms Course 2 A histogram is a bar graph that shows the frequency of data within equal intervals. There is no space between the bars in a histogram.

21. 1-4 Bar Graphs and Histograms Number of Hours of TV 1 // 2 //// 3 //// //// 4 //// / 5 //// /// 6 /// 7 //// //// 8 /// 9 //// Frequency Number of Hours of TV Course 2 Additional Example 3: Making a Histogram The table below shows the number of hours students watch TV in one week. Make a histogram of the data. Step 1: Make a frequency table of the data. Be sure to use equal intervals. 1–3 15 17 4–6 7–9 17

22. 1-4 Bar Graphs and Histograms Frequency Number of Hours of TV 1–3 15 17 4–6 7–9 17 Course 2 Additional Example 3 Continued Step 2: Choose an appropriate scale and interval for the vertical axis. The greatest value on the scale should be at least as great as the greatest frequency. 20 16 12 8 4 0

23. 1-4 Bar Graphs and Histograms Frequency Number of Hours of TV 1–3 15 17 4–6 7–9 17 Course 2 Additional Example 3 Continued Step 3: Draw a bar graph for each interval. The height of the bar is the frequency for that interval. Bars must touch but not overlap. 20 16 12 8 4 0

24. 1-4 Bar Graphs and Histograms Frequency Number of Hours of TV 1–3 15 17 4–6 7–9 17 Course 2 Additional Example 3 Continued Step 4: Label the axes and give the graph a title. Hours of Television Watched 20 16 12 8 4 0 Frequency 7–9 1–3 4–6 Hours

25. 1-4 Bar Graphs and Histograms Number of Hats Owned Frequency 1 // 2 //// 3 //// / 4 //// / 5 //// /// 6 //// 7 //// / 8 //// //// 9 //// //// Frequency Number of Hats Owned Course 2 Try This: Example 3 The table below shows the number of hats a group of students own. Make a histogram of the data. Step 1: Make a frequency table of the data. Be sure to use equal intervals. 1–3 12 18 4–6 7–9 24

26. 1-4 Bar Graphs and Histograms Frequency Number of Hats Owned Course 2 Try This: Example 3 Step 2: Choose an appropriate scale and interval for the vertical axis. The greatest value on the scale should be at least as great as the greatest frequency. 30 25 20 15 10 5 0 1–3 12 18 4–6 7–9 24

27. 1-4 Bar Graphs and Histograms Frequency Number of Hats Owned Course 2 Try This: Example 3 Step 3: Draw a bar graph for each interval. The height of the bar is the frequency for that interval. Bars must touch but not overlap. 30 25 20 15 10 5 0 1–3 12 18 4–6 7–9 24

28. 1-4 Bar Graphs and Histograms Frequency Number of Hats Owned Course 2 Try This: Example 3 Number of Hats Owned Step 4: Label the axes and give the graph a title. 30 25 20 15 10 5 0 Frequency 1–3 12 18 4–6 7–9 24 7–9 1–3 4–6 Number of Hats

29. 1-4 Bar Graphs and Histograms Number of Laps Run 8 6 4 2 0 Number of Students 0–4 5–9 15–19 10–14 Number of Laps Course 2 Lesson Quiz: Part 1 1. The list shows the number of laps students ran one day. Make a histogram of the data. 4, 7, 9, 12, 3, 6, 10, 15, 12, 5, 18, 2, 5, 10, 7, 12, 11, 15

30. 1-4 Bar Graphs and Histograms Average Number of Laps Run 16 12 8 4 0 Average Number of Laps Run 1990 1995 2000 Boys 12 11 15 Girls 10 8 12 Number of Laps 1995 1990 2000 Boys Girls Course 2 Lesson Quiz: Part 2 2. Make a double-bar graph of the data in the table.